2001 NISSAN ALMERA ECU

SEF074X
Overall Function CheckNJEC0242Use this procedure to check the overall function of the three way
catalyst. During this check, a 1st trip DTC might not be confirmed.
Without CONSULT-II
1) Start engine and drive vehicle at a speed of more than 70 km/h
(43 MPH) for 2 consecutive minutes.
2) Stop vehicle with engine running.
3) Set voltmeters probes between ECM terminals 62 (HO2S1
signal), 63 (HO2S2 signal) and engine ground.
4) Keep engine speed at 2,000 rpm constant under no load.
5) Make sure that the voltage switching frequency (high & low)
between ECM terminal 63 and engine ground is much less
than that of ECM terminal 62 and engine ground.
Switching frequency ratio = A/B
A: Heated oxygen sensor 2 (rear) voltage switching fre-
quency
B: Heated oxygen sensor 1 (front) voltage switching fre-
quency
This ratio should be less than 0.75.
If the ratio is greater than above, it means three way catalyst
does not operate properly.
NOTE:
If the voltage at terminal 62 does not switch periodically more
than 5 times within 10 seconds at step 4, perform trouble
diagnosis for DTC P0133 first. (See EC-236.)
Diagnostic ProcedureNJEC0243
1 CHECK EXHAUST SYSTEM
Visually check exhaust tubes and muffler for dent.
OK or NG
OK©GO TO 2.
NG©Repair or replace.
DTC P0420 THREE WAY CATALYST FUNCTIONQG
Overall Function Check
EC-360

SEF196Y
With CONSULT-II
1) Start engine
2) Read ªVHCL SPEED SEº in ªDATA MONITORº mode with
CONSULT-II. The vehicle speed on CONSULT-II should
exceed 10 km/h (6 MPH) when rotating wheels with suitable
gear position.
3) If NG, go to ªDiagnostic Procedureº, EC-375.
If OK, go to following step.
4) Select ªDATA MONITORº mode with CONSULT-II.
5) Warm engine up to normal operating temperature.
6) Maintain the following conditions for at least 10 consecutive
seconds.
ENG SPEED 2,600 - 4,000 rpm (M/T)
2,600 - 3,000 rpm (A/T)
COOLAN TEMP/S More than 70ÉC (158ÉF)
B/FUEL SCHDL 5.3 - 10.7 msec (M/T)
4.8 - 10.7 msec (A/T)
Selector lever Suitable position
PW/ST SIGNAL OFF
7) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-375.
With GST
Follow the procedure ªWith CONSULT-IIº above.
SEF607Y
Without CONSULT-II
1) Lift up drive wheels.
2) Start engine.
3) Read the voltage signal between ECM terminal 86 (Vehicle
speed sensor signal) and ground with oscilloscope.
4) Verify that the oscilloscope screen shows the signal wave as
shown in the figure.
5) If NG, go to ªDiagnostic Procedureº, EC-375.
DTC P0500 VEHICLE SPEED SENSOR (VSS)QG
DTC Confirmation Procedure (Cont'd)
EC-371

3) Select ªCLSD THL/P SWº in ªDATA MONITORº mode. If
ªCLSD THL/P SWº is not available, go to step 5.
4) Check the signal under the following conditions.
Condition Signal indication
Throttle valve: Idle position ON
Throttle valve: Slightly open OFF
If the result is NG, go to ªDiagnostic Procedureº, EC-388.
If OK, go to following step.
5) Select ªDATA MONITORº mode with CONSULT-II.
6) Drive the vehicle for at least 5 consecutive seconds under the
following condition.
THRTL POS SEN More than 2.3V
VHCL SPEED SE More than 4 km/h (2 MPH)
Selector lever Suitable position
Driving pattern Driving vehicle uphill (Increased engine load)
will help maintain the driving conditions
required for this test.
7) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-388.
SEF090X
Overall Function CheckNJEC0291Use this procedure to check the overall function of the closed
throttle position switch circuit. During this check, a 1st trip DTC
might not be confirmed.
Without CONSULT-II
1) Start engine and warm it up to normal operating temperature.
2) Check the voltage between ECM terminal 40 (Closed throttle
position switch signal) and ground under the following condi-
tions.
Condition Voltage
At idle Battery voltage
At 2,000 rpm Approximately 0V
3) If NG, go to ªDiagnostic Procedureº, EC-388.
DTC P0510 CLOSED THROTTLE POSITION SWITCH (WHERE FITTED)QG
DTC Confirmation Procedure (Cont'd)
EC-386

SEF174Y
PROCEDURE FOR MALFUNCTION A=NJEC0344S01With CONSULT-II
1) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Verify that ªCOOLAN TEMP/Sº is less than 50ÉC (122ÉF).
If the engine coolant temperature is above the range, cool
the engine down.
4) Start engine and let it idle for at least 5 seconds.
5) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-423.
With GST
Follow the procedure ªWith CONSULT-IIº above.
SEF200Y
PROCEDURE FOR MALFUNCTION BNJEC0344S02CAUTION:
Always drive vehicle at a safe speed.
TESTING CONDITION:
Always perform the test at a temperature above þ10ÉC (14ÉF).
With CONSULT-II
1) Start engine and warm it up to above 80ÉC (176ÉF).
2) Select ªEGR VOL CONT/Vº in ªACTIVE TESTº mode with
CONSULT.
3) Hold engine speed at 1,500 rpm.
4) Touch ªQuº and set the EGR volume control valve opening to
50 step and check EGR TEMP SEN.
EGR TEMP SEN should decrease to less than 1.0V.
If the check result is NG, go to ªDIAGNOSTIC PROCEDUREº,
EC-423.
If the check result is OK, go to the following step.
SEF201Y
5) Turn ignition switch ªOFFº and wait at least 9 seconds.
6) Start engine and maintain the following conditions for at least
5 consecutive seconds.
ENG SPEED Above 2,400 rpm
VHCL SPEED SE Above 90 km/h (56 MPH) or more
B/FUEL SCHDL 4.0 - 4.8 msec
Selector lever Suitable position
7) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-423.
DTC P1401 EGR TEMPERATURE SENSOR (WHERE FITTED)QG
DTC Confirmation Procedure (Cont'd)
EC-419

With GST
1) Start engine and warm it up to normal operating temperature.
2) Turn ignition switch ªOFFº and wait at least 9 seconds, then
turn ªONº.
3) Select ªMODE 1º with GST and maintain the following condi-
tions for at least 5 consecutive seconds.
Engine speed Above 2,400 rpm
Vehicle speed Above 90 km/h (56 MPH)
Selector lever 4th or 5th
4) Select ªMODE 7º with GST
5) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-423.
DTC P1401 EGR TEMPERATURE SENSOR (WHERE FITTED)QG
DTC Confirmation Procedure (Cont'd)
EC-420

SEF213Y
2) Select ªP/N POSI SWº in ªDATA MONITORº mode with CON-
SULT-II. Then check the ªP/N POSI SWº signal under the fol-
lowing conditions.
Position (Selector lever) Known-good signal
ªNº and ªPº (A/T only) position ON
Except the above position OFF
If NG, go to ªDiagnostic Procedureº, EC-440.
If OK, go to following step.
3) Select ªDATA MONITORº mode with CONSULT-II.
4) Start engine and warm it up to normal operating temperature.
5) Maintain the following conditions for at least 50 consecutive
seconds.
ENG SPEED 1,550 - 4,000 rpm
COOLAN TEMP/S More than 70ÉC (158ÉF)
B/FUEL SCHDL 3.0 msec or more
VHCL SPEED SE 70 - 130 km/h (43 - 81 MPH)
Selector lever Suitable position
6) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-440.
SEF137X
Overall Function CheckNJEC0429Use this procedure to check the overall function of the park/neutral
position switch circuit. During this check, a 1st trip DTC might not
be confirmed.
Without CONSULT-II
1) Turn ignition switch ªONº.
2) Check voltage between ECM terminal 42 (PNP switch signal)
and body ground under the following conditions.
Condition (Gear position) Voltage (V) (Known good data)
ªPº (A/T only) and ªNº position Approx. 0
Except the above positionA/T models
BATTERY VOLTAGE
(11 - 14V)
M/T models
Approximately 5
3) If NG, go to ªDiagnostic Procedureº, EC-440.
DTC P1706 PARK/NEUTRAL POSITION (PNP) SWITCHQG
DTC Confirmation Procedure (Cont'd)
EC-438

Diagnostic ProcedureNJEC1238
1 CHECK OVERALL FUNCTION-I
1. Start engine and drive the vehicle at over 70 km/h (43 MPH) for 2 consecutive minutes.
2. Stop vehicle and keep the engine running.
3. Set voltmeter probes between ECM terminals 63 [HO2S2 (B1) signal] and ground.
4. Check the voltage while revving up to 4,000 rpm under no load at least 10 times.
(Depress and release the accelerator pedal as quickly as possible.)
SEF240Z
OK or NG
OK©INSPECTION END
NG©GO TO 2.
2 CHECK OVERALL FUNCTION-II
Keep engine at idle for 10 minutes, then check the voltage between ECM terminal 63 and ground, or check the voltage
when coasting at 80 km/h (50 MPH) in 3rd gear (M/T), ªDº position with ªODº OFF (A/T).
SEF240Z
OK or NG
OK©INSPECTION END
NG©GO TO 3.
HEATED OXYGEN SENSOR 2 (REAR)QG
Diagnostic Procedure
EC-465

6 CHECK GROUND CIRCUIT
1. Check harness continuity between heated oxygen sensor 2 (rear) harness connector terminal 4 and body ground.
Refer to wiring diagram.
Continuity should exist.
2. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 7.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
7 CHECK HEATED OXYGEN SENSOR 2 (REAR)
Refer to ªComponent Inspectionº, EC-467.
OK or NG
OK©GO TO 8.
NG©Replace heated oxygen sensor 2 (rear).
8 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-177.
©INSPECTION END
SEF662Y
Component InspectionNJEC1239HEATED OXYGEN SENSOR 2 (REAR)NJEC1239S01With CONSULT-II
1) Start engine and drive vehicle at a speed of more than 70 km/h
(43 MPH) for 2 consecutive minutes.
2) Stop vehicle with engine running.
3) Select ªFUEL INJECTIONº in ªACTIVE TESTº mode, and
select ªHO2S2 (B1)º as the monitor item with CONSULT-II.
4) Check ªHO2S2 (B1)º at idle speed when adjusting ªFUEL
INJECTIONº to±25%.
ªHO2S2 (B1)º should be above 0.68V at least once when
the ªFUEL INJECTIONº is +25%. ªHO2S2 (B1)º should be
below 0.56V at least once when the ªFUEL INJECTIONº is
þ25%.
CAUTION:
+Discard any heated oxygen sensor which has been
dropped from a height of more than 0.5 m (19.7 in) onto a
hard surface such as a concrete floor; use a new one.
+Before installing new oxygen sensor, clean exhaust sys-
tem threads using Oxygen Sensor Thread Cleaner tool
and approved anti-seize lubricant.
SEF244YA
HEATED OXYGEN SENSOR 2 (REAR)QG
Diagnostic Procedure (Cont'd)
EC-467